Sif happens! Those badass investigators on Marvel's Agents of S.H.I.E.L.D.will soon meet their match when attacked by Lorelei (Elena Satine), a deadly, flame-tressed vixen from the Thor comics. But, never fear, Lady Sif is here! Actress Jaimie Alexander, who played the bodacious warrior-goddess in the movies Thorand Thor: The Dark World, will reprise her role on the ABC series as Sif tries to save the S.H.I.E.L.D. team. The episode, titled "Yes Men," is scheduled to air March 11.

"We always have our radar up for ways to tie our series into the Marvel films and bringing in an Asgardian really cements that connection," says executive producer Jed Whedon. "Lady Sif comes here on a hunting mission — sent by Odin — to find her arch-enemy Lorelei and bring her back to Asgard. It throws our agents for a loop when they find themselves in a fight right alongside this powerful woman from Thor's world."

The cast and crew were pretty wowed, too. "Jaimie walked onto the set in full Lady Sif regalia just as she looks in the movies — from the huge, mile-high boots to the metal armor — and she towered over everyone," says executive producer Maurissa Tancharoen. "It was so striking and impressive, all we could do was stare. It was very cool!"